The disclosure relates to a developing cartridge which is provided with a developing roller and a gear which transmits driving force to the developing roller.
A developing cartridge provided with a developing roller, a developing roller gear which rotates integrally with the developing roller, and a driving input gear which applies driving force to the developing roller gear is known (for example, see Japanese Unexamined Patent Application Publication No. 2010-134330).
In particular, in this developing cartridge, rotation of the driving input gear is transmitted to the developing roller gear via a supply roller gear and an idle gear. In this configuration, the driving input gear and the idle gear are directly supported by a housing of the developing cartridge whereas the supply roller gear is fixed to an axis of a supply roller, and the axis of the supply roller is supported by a separate bearing which is fixed to the housing.